A primary tunnel in an Ethernet network may relay packets from a first packet switch through a network of intermediate packet switches to a second packet switch. Often, a backup tunnel is provisioned between the first packet switch and the second packet switch to provide a redundant path by which packets may be relayed from the first packet switch to the second packet switch. The backup tunnel may traverse a physically different path than the primary tunnel through the network of intermediate packet switches to reduce the possibility that an outage affecting the primary tunnel will also affect the backup tunnel.
In some packet switch networks, only one of the primary tunnel and backup tunnel is active at a time. If the packet switches at either end of the tunnels do not agree with respect to which of the tunnels is the active tunnel, communication problems may ensue. For example, if the first packet switch considers the primary tunnel to be active, the first packet switch may forward packets to a second packet switch via the primary tunnel. However, if the second packet switch considers the primary tunnel to be inactive, the second packet switch may drop packets received from the primary tunnel, thereby preventing communication between the packet switches.